Vacuum tube



Feb. 9 1926. 1,572,530

" w. F. HENDRY VACUUM TUBE Fi led Dec. 28, 1918 //7 van for: W/'///'a/77f fiend/y. y

Patented Feb. 9, 1926.

UNITED STATES PATENT OFFICE.

WILLIAM F. HENDRY, OF NEW YORK, N. Y., ASSIGIN'OR TO WESTERN ELECTRICCOM- IPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

VACUUM TUBE.

Application filed December 28, 1918. Serial No. 268,876.

To all whom it may concem:

Be it known that I, lVILLIAM F. HENnnY,

a citizen of the United States, residing at New York, in the county ofNew York, State of New York, have invented certain new and usefulImprovements in Vacuum Tubes, of which the following is a full, clear,concise, and exact description.

This invention relates to improvements in vacuum tubes, and moreparticularly to the mounting of the terminal connections for theleading-in wires of a vacuum tube.

The end of the vacuum tube having the leading-in wires is usually formedwith an elongated portion or neck and this is surrounded by a shellhaving a base piece on which are mounted terminal connections for theleading-in wires to the various electrodes of the tube.

Heretofore it has been the practice to secure the shell and correlatedparts in position on the tube by means of sealing wax, which is pouredinto the shell in such a manner as to fill all the intervening space. Ithas been found in the use of the tubes that at the temperatures whichare sometimes reached this sealing material is melted with consequentfailure of proper operation.

It is the object of this invention to remedy 30 this defect. The objectis attained by attaching the shell to the tube by means of a relativelysmall body of cement having a high melting point such as a mixture ofPortland cement and shellac and by closing the outer end of the shellwith a cap of insulating material, such as micarta, having a highmelting point relative to sealing wax. The leading-in wires of the tubeare attached tocontract terminals which may be mounted on an insulatingspider or Web as heretofore and which extend through openings in the capabove referred to. \Vhen the cap has been placed in position with theterminals extending therethrough, it is secured by turning or spinningthe endof the shell inwardly, the. cap being provided in the preferredform with a peripheral groove for the reception of the flange thusformed.

These and other novel features of the structure will be betterunderstood from the following detail description taken in connectionwith the accompanying drawings, in which Fig. 1 is a side elevation withparts broken away of a vacuum tube to which the shell has been applied,but before the insulating web and cap have been placed in position.Figs. 2 and 3 are a plan and elevation respectively of the insulatingweb. Figs. 4 and 5 are a bottom plan and vertical section respectivelyof the insulating cap. Fig. 6 is an enlarged perspective partly brokenaway of the shell in its co-.nplete l form.

As shown in Fig. 1 the glass bulb 10 consuch as cement and shellac 19 isplaced between the sleeve and the neck and tamped firmly in place by anysuitable instrument through the open end of the sleeve. A web 20 ofinsulating material having contact posts 21 mounted thereon and clips 22at the base of the contact posts is placed on the .shoulder 16, beingadjusted to its proper position by means of a notch 23 in the web and acooperating projection 24 pressed inwardly in the sleeve. It will beunderstood that the base of the tube is adapted to be inserted in asocket (not shown) which has a series of spring contacts for the contactposts, and is locked therein by n'ieansof a bayonet joint one member ofwhich is shown in the projection 29. It will be seen therefore that thenotch 23 and projection 24, or equivalent means, are desirable to insurethe proper position of the contact posts. An illustration of a socketwhich may be used with this tube is described in U. S. Patent 1,325,865of Herbert E. Shreeve, issued Dec. 23. 1919. The leading-in wires 25 arethen attached to the clips 22 in any suitable manner. for instance bysoldering. A cap 26 of micarta or any desired insulating material isplaced upon the web 20, the contact posts extendiig through openings 27in the cap. The n1elting point of cap 26 is higher than any temperatureto which the tube will be subjected and is preferably higher than themelting point of sealing wax which has been used heretofore. -This istrue also of the sealing ltltl material 19 and the web 20. A groove 28is formed in the periphery of the cap and when the cap is in positionthe outer end of the sleeve is turned or spun into this groove so as tohold the parts rigidly in position and at the same time to protect theend ol the sleeve by the over-hanging side of the groove 28. As shown inFigure 5, the plate 26 is very thin relative to its diameter.

This invention is not limited to the form described above for it isevident to one skilled in the art that various modifications may he madetherein without departing in any wise from the spirit of this inventionas defined in the appended claims.

V hat is claimed is:

1. A vacuum tube comprising a metal sleeve surrounding the neck of thetube and secured thereto by means of sealing material placcd betweensaid neck and sleeve. and an insulating cap fitted in the end of saidsleeve, said cap having openings therethrough for the passage of theelectrical connections of the tube and having a peripheral groove, theend of said sleeve be ing turned inwardly into said groove.

'2. A vacuum tube comprising a metal sleeve secured to the neck of thetube, said sleeve having an annular shoulder near its outer end, aninsulating web engaging said shoulder, contact terminals on said web,connections from said terminals to the in terior of the tube, a cap ofinsulating material fitted in the end of said sleeve, said ca havingopenings for the protrusion of said contact terminals and means forsecuring said cap in position.

3. A vacuum tube comprising a. metal sleeve secured to the neck of thetube, said sleeve having an annular shoulder near its outer end, aninsulating web engaging said shoulder, contact terminals on said web,connections from said terminals to the interior of the tube, and a capof insulating material fitted in the end of said sleeve, said cap havingopenings for the protrusion of said contact terminals and having aperipheral move, the end of said sleeve beingturne inwardly into saidgroove.

4. vacuum tubecomprising a metal sleeve surrounding the neck of the tubeand secured thereto by means. of sealing material placed between saidneck and sleeve, said sleeve having an annular shoulder near its outerend, an insulating web ,engaging said shoulder, cont act terminals onsaid web, connections from said terminals to the interior of the tube,and a cap of insulating said cap having openings for the protrusion ofsaid contact terminals and having a peripheral groove, the end of saidsleeve being turned inwardly into said groove.

5. A vacuum tube comprising a metal sleeve secured to the neck of thetube by sealing wax placed between said sleeve and said neck, a thinmicarta late fitted in the end of said sleeve, said ate having openingstherethrough for tlie passage of the electrical connections of the tube'and having a ieripheral groove, the end of said sleeve eing turnedinwardly into said groove.

6. A vacuum tube comprisim a metal sleeve secured to the neck of thetube, a plate of insulating material fitted in the end of said sleeve, aterminal bearing plate fitted in said sleeve adjacent said first plate,said first plate having openings therethrough for the protrusion of saidterminals, said second plate having cutaway portions.

7. A base for a vacuum tube comprising a shell having parallel ridges, alurality of discs of insulating material therebetween, and terminals onone of said discs projecting through the other disc.

8. A base for a vacuum tube comprising a metal shell, a ridge thereon,an insulating member carrying a terminal and sup orted by said ridge,and an insulator carried by said shell having an aperture therein forreceiving said terminal.

9. A vacuum tube base comprising a metal shell, an apertured insulatingmember closing one end of said shell, a, second insulating membermounted in saidshell adjacent said first insulating member, and terminalpins carried by said second insulatin member, said terminal insprojecting through the a ertures in said first insulating member andeyond the end of said shell.

10. A vacuum tube com rising a neck, a metal shell secured to said neck,and an end piece for said shell, the faces of said end piece having adiameter greater than that of the end of said shell.

'11. A vacuum tube comprising a neck, a metallic shell surrounding saidneck and having parallel ridges; a pluralityof discs of insulatingmaterial interposed between said ridges and terminal members carried byone of said discs and projecting through apertures in the other of saiddiscs;

In witness whereof, I hereunto subscribe my name this 27th day ofDecember A. D.,

